> ## Documentation Index
> Fetch the complete documentation index at: https://lightdash-refactor-full-audit-reorg.mintlify.site/llms.txt
> Use this file to discover all available pages before exploring further.

# Run a dedicated scheduler worker

<Note>
  🛠 This page is for engineering teams self-hosting their own Lightdash instance. If you want to set up scheduled deliveries, go to the [Scheduled deliveries](/explore/create-scheduled-deliveries) guide.
</Note>

By default, the Lightdash backend runs scheduled jobs in-process. In production, run a **dedicated scheduler worker** so a heavy dashboard export can't starve the API. Run one through the Helm chart's built-in worker, or as a standalone process you start yourself.

## Helm chart

Set `scheduler.enabled: true` and the chart deploys a dedicated scheduler worker:

```yaml theme={null}
scheduler:
  enabled: true
  replicas: 1            # scale up if deliveries queue at peak times
  concurrency: 3         # jobs per replica (sets SCHEDULER_CONCURRENCY)
  resources:
    requests:
      cpu: 500m
      memory: 1425Mi
      ephemeral-storage: 1Gi
```

When `scheduler.enabled: true`, the chart automatically sets `SCHEDULER_ENABLED: "false"` on the backend — don't set it yourself. Tune delivery throughput with `SCHEDULER_JOB_TIMEOUT`, `SCHEDULER_SCREENSHOT_TIMEOUT`, and `scheduler.tasks.include` / `scheduler.tasks.exclude` to shard task types across worker groups. See the [scheduler environment variables](/self-host/customize-deployment/environment-variables#scheduler) for the full reference.

## Standalone worker

For infrastructure that doesn't use the Helm chart, run the scheduler worker as a separate process.

### 1. Disable the scheduler worker in the main server

Set the following environment variable value:

```bash theme={null}
SCHEDULER_ENABLED=false
```

### 2. Run the standalone scheduler worker

Command to start scheduler worker:

```bash theme={null}
yarn workspace backend scheduler
```

Note that it expects the same environment variables as the main server.

### Example docker-compose.yml

```yaml theme={null}
version: "3.8"
x-environment: &commonEnvironment
  - PGHOST=${PGHOST:-db}
  - PGPORT=${PGPORT:-5432}
  - PGUSER=${PGUSER:-postgres}
  - PGPASSWORD=${PGPASSWORD}
  - PGDATABASE=${PGDATABASE:-postgres}
  - SECURE_COOKIES=${SECURE_COOKIES:-false}
  - TRUST_PROXY=${TRUST_PROXY:-false}
  - LIGHTDASH_SECRET=${LIGHTDASH_SECRET}
  - PORT=${PORT:-8080}
  - SITE_URL=${SITE_URL}
  - EMAIL_SMTP_HOST=${EMAIL_SMTP_HOST}
  - EMAIL_SMTP_PORT=${EMAIL_SMTP_PORT}
  - EMAIL_SMTP_SECURE=${EMAIL_SMTP_SECURE}
  - EMAIL_SMTP_USER=${EMAIL_SMTP_USER}
  - EMAIL_SMTP_PASSWORD=${EMAIL_SMTP_PASSWORD}
  - EMAIL_SMTP_ALLOW_INVALID_CERT=${EMAIL_SMTP_ALLOW_INVALID_CERT}
  - EMAIL_SMTP_SENDER_NAME=${EMAIL_SMTP_SENDER_NAME}
  - EMAIL_SMTP_SENDER_EMAIL=${EMAIL_SMTP_SENDER_EMAIL}
  - HEADLESS_BROWSER_HOST=headless-browser
  - HEADLESS_BROWSER_PORT=3000
services:
  headless-browser:
    image: browserless/chrome
    restart: always
    ports:
      - "3001:3000"

  db:
    image: postgres
    restart: always
    environment:
      POSTGRES_PASSWORD: ${PGPASSWORD}
      POSTGRES_USER: ${PGUSER:-postgres}
      POSTGRES_DB: ${PGDATABASE:-postgres}
    volumes:
      - db-data:/var/lib/postgresql/data

  lightdash:
    image: lightdash/lightdash:latest
    depends_on:
      - db
    environment:
       <<: *commonEnvironment
       SCHEDULER_ENABLED: 'false'
    volumes:
      - "${DBT_PROJECT_DIR}:/usr/app/dbt"
    ports:
      - ${PORT:-8080}:${PORT:-8080}

  scheduler:
    image: lightdash/lightdash:latest
    entrypoint: ["yarn", "workspace", "backend", "scheduler"]
    depends_on:
      - db
    environment: *commonEnvironment

volumes:
  db-data:
```